Excavator shovel



Jufiy 28, 1925.

P. H. THOMAS EXCAVATOR sHbvEL I s Sheets-Sheet 1 Original Filed Sept. 8,1922 IN V EN TOR s ATTORNE Y5 July 28, 1925. 1,547,533-

P. H. THOMAS EXCAVATOR SHOVEL Original Filed Sept. 8, 1922 3Sheets-Sheet 2 W INVENTOR 64 BY 3 M, M, M 9 M fl/s ATTORNEY6 li atentedJuly 2%, i925,

PERCY H. THOMAS, 0F UPPER MGNTCIQAIR, NEW JERSEY, ASSIGNQR GUGG-Elltmtt.

' BRGTHERS, OF NEW YORK, N. '31, A GQPART i shill nxoavaron snovnnapplication filed September 8, 1922, Serial No. teases. Renewed June 19,W85,

To all whom it may concern:

Be it known that l, Pnnor- THoMAs, a citizen of the UnitedStates,residing at Upper Montclair, in'the county of Essex,

State of Newrllersey, have inventedcertain new and usefullmprovementsfin Excavator Shovels; and I do hereby declare the followmgto be a full, clear, and exact description of the invention, such aswill enable others skilled in'the art to which it. appertains to 7 makeand use the same.

This invention relates to excavating shov els and, more particularly, topower operatedshovels used largely in open diggings, and also in minesand-in sub-aqueous work. The invention has for its object the provisionof an improved excavating shovel.

Such excavators of the prior art comprise a turntable resting upon asuitable body structure, a boom mounted upon this turntable, a dipperstick carried by the boom and a dipper that is rigidly secured to theend of the boom. The dipper is manipulated in three movements,reciprocating relatively to the boom, hoisting, and swinging. Thereciprocating movementrelative to. the boom is accomplished by meansof apinion driven by a shipper shaft which is carried by the boom, thispinion cooperating-1 with a-rack on the dipper stick. The hoisting, isac-' complished by the cooperative action of the rack and pinion and ahoisting cable attached to the dipper, or to the dipper stick, near itsouter end, which passes over a sheave carried on the upper end of'theboom. The swinging movement of the dipper is eftected by applying aturning moment to the turntable in. any convenient manner. It is ofgreat importance for the efiicient operation of an excavator to.increase the ratio of the actual diggin' time to the time required forthe complete igging cycle. In most excavators of the prior art all threeof the above mentioned movements are essential elements of. the normaldigging cycle. The dipper is forced, in the outward ,part of itsreciprocating movement, into the ground b .means of the rack .andpmion,and, b t ese elements, is held agalnstthe groun or bank" to be removed,while the hoisting cable moves it upwardly to fill the dipper. When thedipper 1s filled 1t 1s swung around, by therotation of the turntable, toa dischargeposition over the receiving vehicle which is usually on thesame or a parallel track with the shovel. The dipper then has to beswung back, reciprocated inwardly and lowered beforev it is ready tocommence another digging stroke. The angle of this swing notinfrequently amounts to as much as 120, in which case the time consumedby the swinging around is from 4:0 to 50% ot the time'required for thetotal digging cycle,

In the remainmg prior art excavators the swinging movement has beeneliminated, or

partially eliminated,at the expense. of -in-' creasing the hoistingelement of the cycle.

In this type of excavator the load of. the

dip er isdischarged into a hopper located at t e center, of theexcavator whlch delivers it to the receiving vehicle, either directly,or by means of a conveyor belt. lilowever, theseexcavators, in order todeposit the dipper load in the hopper, raise it until the material willslide by gravity through a chute connecting the" dipper with the-hopper.This requires not onlyconsiderable time,

which is roughly equal to theswinging time of the previously mentionedtypev of excavator, but also requires considerable power. An idea-of theamount oi power consumed can be had when it is considered :that the diper, 'of the larger sizes of excavators, holds approximately 20 cubicyards of maas I terial, whichweighs some 35 tons, and which must behoisted to a height of about feet above the level of the dump car.Moreover,

the descent of this load, along a s'tee chute froma height of 80 feetmay cause amage to the excavator and the receiving vehicle, as well aswear of the; chute.

According tomy necessity for either resent invention the substantiallystraight pathjto a position I oisting, in order to 7 cause the dipperload to slide down a chute, .or swinging, is eliminated by soconstructing the excavator as to carry the loaded dipwhere it. is againready to immediately com- 3 mence another digging stroke; This can notbe accom lished practically by an ordinary power s ovel, inasmuch as thedipper is rigidly attached to the dipper stick, and consequently, therange of movement of the dip er without spilling its contents, islimited The dipper of my improved shovel, however, may be actuated in asingle vertical plane. through all the movements of a complete diggingcycle.

This is accomplished, in my improved excavator, first, by dischargingthe loaded dipper at a central point relative to the digging circle;second, by providing means for actuating the. dipper so as to move it ina substantially straight path from the point of completion of thedigging stroke to the central discharge position, and third, by soconstructing the actuating devices of the dipper that they will maintainit in a sufliciently upright position substantially to prevent spilling,even though the dipper be moved up close to the base of the boom inorder to reach the discharge position.

The clip er may discharge directly into 'a receiver ocated centrallywith respect to the digging circle of the excavator, such, for example,as a car or motor truck placed directly in frontof the boom ad'acent thecavated material passes to the receiving ve-J vgmg'stroke, in orderto-bring -'over the hopper or discharge opening.

side of the excavator body, but pre erably the excavator itself isprovided with a discharge hopper or opening through which the ex hiclebeneath. This hopper or discharge opening is located in the vicinity ofthe base of the boom and referably directly in front of it. The mecianism ,for actuating the dip er is so constructedzthat the dipper 'sticmay be swung into a substantially vertical position, or even through thevertical so that its lower end points in the opposite direction to thatassumedduring the digthe dipper Means are provided to automatically movethe dipper angularly with respect to the dipper stick, during thismovement, to maintain the dipper in an upright position as it is movedtoward the hopper so as substantiallyto prevent spilling of itscontents.

The hopperis preferably carried by the turntable rather than by the bodyof the excavator. This reduces the size and weight duced, and it is,

of the hopper because it need not be symmetrical in shape since, when somounted, thefhoppe'rfirotates with the shovel which, therefore, alwaysdischarges at about the same place in the hopper;

. It is also advantageous to mount the boom at a point a distance backfrom-the front of 7 the turntablerath'er than attaching it at,

or closeto, the front of the turntable as is customary in excavatorspreviously constructed. By this arrangement the stresses in theexcavator structure are materially retherefore, possible to in- Fig. 1is a view partly in-elevation and partly in section showing an excavatorconstructed in accordance with the preferred 'form of my invention;

Fig. 2 is an enlarged view bf the end of the dipper stick, with thedipper attached,

illustrating in detail the preferred mecha nism for pivotally the dipperstick.

Fi 3 is an enlarged view of a portion of the oom and dipper stick showinthe mechanism for reciprocating the stick, and for moving the auxiliarydipper stick relative to the main dipper stick for the purpose ofrotating the dipper about its pivot to maintain it in an uprightposition;

Figsmi and 5 are views showing an excavating machine of modifiedconstruction; Fig. 6 is a view partly in elevation and partly insect-ion of an excavator somewhat attaching the dipper to ipper similarto the type shown in Fig. 1, but

adapted to make Figs. 7 and 8 tion of the means for controlling therotation of the dipper about its pivot.

Referring now to these drawings, the excavator is adapted to travel upona four-rail track 10, and a second track 11 is provided an extra widethrough cut;

for the receiving car 12. Both of these tracks may be of any desiredgauge. The trucks 13 are of the 4 wheel type, and there are rovided fourof these trucks upon which the dy 14 of the excavator is supported.

This body is built up of suitable steel shapes and plates to furnish therequired strength, and is connected with the trucks 13 by means of theraised pillars 15 which elevate thebody of the excavator sufficiently toallowthe receiving vehicle 12 (which may be a standard railroad car). topass freely thereunder. On the u ward part of the body 14 there isprovided by means of the double These double flanged rollers are equallyspaced around the cular track .16 to allow the turntable 17 to be easilyrotated. This turntable is also constructed of steel sections suitablyproportioned to carry the weight of the operating parts of theexcavator, and to withstand the racking stresses which are caused by the1 ,operatlon of the dipper.

illustrate another modifica-,

entire length of the cir-.

a circular track 16' upon which the turntable 17 is supported flangedrollers 18.

for the dipper, and in which t ere 1s pro- 0 harness vided a suitablespace for the operator, from which he has a clear view of the workings Ymanner by means of the cable 22, cooperatmg with the A frame 23, and thebrace 24;. Since an end. view only ofthe A frame 23 is shown, only oneof the two legs thereof which go down to the sides of the turntable 17can be seen.

Carried by the boom 20, at about the' center thereof, is the dip orstick 24 which is slidably connected to t e boom by means of triangularplates 25, which are pivoted to the shipper" shaft 26,"'carried,insuitable bearin upon the steel frame work 27 which is mounted upon theboom. Rigidly attached to the shipper shaft 26 is the pinion 28 whichcooperates with the teeth of a rack 21 (Fig. 3) carried on the undersideof the dipper stick 24. An electric or other motor 29 drives the shippershaft 26 through suitable gearing and thereby reciprocates the dipperstick with respect to the boom to operate the dipper as will behereafter described. The triangular plates 25, one of which is oneachfside of the dipper stick,

are provided with. rollers 30 which cooperate with the upper surface ofthe-dipper stick to keep the rack in mesh with the pinion-28.

The dipper 33 is pivoted at 32 on the end of the dipper stick 24. Thedipper-is held in the proper angular position by .means of the links 34,pivoted one on each side of the dipper at 35, and to the bell cranks 36at 37. A bell crank is provided on each side of the dipper stick andthese bell cranks are pivotally attached to the dipper stick Each link34 and bell crank 36, together, form a toggle joint which is so arrangedthat the toggle is approximately set in the digging positions of thedipper, but, when. the dipper is moved to the dumping or dischargeposition the, toggle is broken. Carried on each side of the dipper stick24 andynear the lower edge thereof, are two auxiliary dipper sticks 38,which are connected respectively to the bell cranks 36 at 39. Theseauxiliary dipper sticks 38 extend to the rear end of the main dipperstick 24, and they are also provided, on their lower surfaces, withracks 40 (Fig. 3) similar to the rack on the main dipper stick. Theteeth of the racks 40 are enga ed by auxiliary pinions 42 rigidl mountedon the shipper shaft 36. Suite lc rollers 31 are also provided tomaintain the engagement between the teeth of these racks and the pinions42. i

The pinions 42 are of larger diameter per shaft 26 is driven by themotor 29, to

conveyed to the dipper 33 through the bell cranks 36and links 24, torotate the dipper about the pivot 32. By means of this mechanism, as isshown to better advantage in Fig. 2, the dipper 33 is maintained insubstantially the same angular position with respect to the dipper stick24, as long as the dipper stick is extended from the boom, that is,toward the outer end of its stroke. However, when the dipper; is drawnin toward the boom, the angular position of'the dipper with respect tothe dipper stick is changed sufficiently so that when the boom is moved,even to a'vertical position, the contents of thedipper are preventedfrom spilling.

Attached to the dipper 33 by'means of a bail 43 is the hoisting cable 44which passes over the sheave 45, located at the outer end of the boom20, thence'to the hoisting drum 46 located in the cabl9. The control .ofthe dipper 33 duringits actual digging cycle is accomplished by means ofthe combined .operation of the hoisting cable 44 and. the dipper stick.24 as is well understood.

. The excavator is provided with a discharge opening or hop 'er 47,which is mounted upon the turnta le 17," at the foot of the boom, andpreferably centrally with With an excavator constructed in this manner acomplete digging cycle can be accomplished as follows: Assuming that the-dipper is in the position shown at A, Fig.

1, itis forced'into the ground by means'of the motor 29 acting throughthe main rack and pinion upon the dipper stick 24 and thanv movedoutwardly by the combined ac-.- tion of the dipper stick 24 and hoistingcable 44. The dipper then proceeds further outward and upward,describing a more or less arcuate path, and is hoisted until the dipperis filled with the earth, or other material to be removed.

The dipper may not be completely filled until it reaches a relativelyhigh position, as indicated at B, but ordinarily it will be- 7 comefilled at some position intermediate between A and B. Regardless,however, of the position at which the digging stroke is completed, it isdesired to discharge the contents of the dipper so as to commenceanother digging stroke, and by means of the improved mechanism thedipper may be moved in a substantiall direct path to the dischargeposition C, directly over the central discharge hopper 47. By propermanipulation of the hoisting cable, and the dipper stick motor 29, thedipper 33 is carried in a substantially straight line from the pointwhere the diggin stroke is completed to the discharge position C, and bymeans of the improved mechanism above described, the dipper ismaintained in an upright position so as to prevent the spilling of thecontents of the dipper until the dipper reaches the discharge position.When the dipper is over the hopper 47, the contents are discharged inthe ordinary manner by releasing the pivoted bottom 48 of the dipper(Fig. 5). As soon as the contents ofthe dipper are discharged the dipperis allowed to drop over the side of the turntable 17 under the controlof the dipper stick and hoisting cable, and returned to the initialposition A in a substantially direct path, to commence another diggingstroke. There is no swinging move-' ment ofthedipper, or of theturntable, as an element of the normal digging cycle. Neither isthereany unnecessary hoisting as an element of the normal diggingJ cycle, because, as soon as the dipper has een hoist ed just suiiiciently to fillthe dipper, it is carried in a substantially straight line from thatspot to the discharge position, and does not have to hev hoisted inorder to cause thematerial to slide down a chute. The only swinging ofthe turntable that is necessary is that required to shift thedipperthrough a relatively few degrees when it isdesired to dig in adifferent vertical :plane. The'mechanism for causing this turning of theturntable has'not been illustrated or described as it is of known con"-1 struction.

Referring now toFigs. 4 and 5, there is here shown an 'excavator, theoperation of which is very similar to that of the excavator previouslydescribed, the difference hem in, the" mechanism for connecting the auxiiary dipper sticks 38 with the dipper in order to actuate the same aboutthe ivot 32. -In both casestoggle joints are use but while" in 1 and 2the auxiliary dipper stick is connected to the bell crank, one part ofwhich forms one-half of. the toggle; in Figs; .4 and 5 the auxiliarydipper stick is connected directly tothe middle ofthe toggle, '-Thetoggle system-.of Figs. 4 and 5- comprises a air of 49, one on each sideof the ipper stick, which operate in conjunction with another similarlydisposed {pair Qf-links 50. The 49 are pivoted 1 on the .bracketbl whichis secured to the main" dipper stick 24. The links 50 are,pivotallyattached to the dipper 33- at 52 jointedwith the lmks 49 at 53.The

operation of the dipper 33 is exactly .auxiliary dipper sticks 38 arerespectively attached to-the common joints 53. The motion of theauxiliary dipper sticks 38 rela tive to the main dipper stick 24 causesthe straightening out or colla sing of the toggle links 49 and 50, depening upon the direction of the motion of the auxiliary dipper sticks.Because of the choice of the relative location of the pivots 41 and 52,the angular movement of the dipper, when the dipper stick is in theoutward, or digging position, is relatively small. Thus, the dipper ismaintained in the proper angular position relative to the main dipperstick during the time that it is in engagement with the bank or material'to be excavated. However, when the dipper has been filled it can bemoved directly to the discharge position C, which is similar to thatshown in Fig. 1, and durinu this movement the dipper is maintained in anupright position to prevent the spilling of its contents, although thedipper sticks 24 and 38 are moved to approximately the verticalposition. The

operation of the excavator shown in Figs. 4 .and 5, is, therefore,substantlally the same as that of the excavator shown in Figs. 1

and 2. Referring to. Fig. 6, there is here illustrated an excavatingmachine which is ca- 'pable of making a wider through out than chargehopper 47, this hopper is provided with a hinged platform 55 which ismovable in the vertical direction. This hinged lplatform is pivoted at56 to the edge of the opper 47, and extends outwardly in front of theturntable 17. Pivotally attached to theboom at 57 are one or more aircylinders 58, each having a piston rod 59 which "is attached by means ofthe spring 60 to the platform 55 at the point 62. By means of this aircylinder 58, the hinged platform 55 may be raised to cause the materialpre- 7 viouslydischarged thereon from the dipper '33, to slide forwardinto the hopper 47, and

thence into the receiving vehicle 12. The

same as-previously described, except that in stead of dischargingdirectl into the ho per. 47, it discharges onto the inged plat orm 55;The shock caused by the fall of the material from. the dipper to theplatform 125 me be absorbed by means of the r g 60-,

an a certain amount of air whic is left in the bottom of the air 0linder 58 for this purpose. The air cylin er 58 is under the control ofthe operator in the cab 19, and

the

, asaaees he may easily regulate the lifting of the platform 55 so asnot to interfere with the normal operation of the dipper 33 as previ'ously described. In other words, the additionof the hingedplatformdoes not, in any manner, lengthen the time of the digging c ole.If it is desired, instead of placing t e control of the air cylinder 58in the hands of the operator, this air cylinder may be caused to beautomatically controlled.

'In any of the types of excavators dc I scribed above, it may be founddesirable, in

order to move the dipper 33 to the proper discharge position over thehopper 47, to

move the dipper stick '24 through the verti'cal position, to a positionwhere the dipper 33 will be at the left (as viewed in the drawings) ofthe center of suspension of the dipper stick on the boom. That is, itmay be means for causin found desirable "to locate the hopper behind thegravity position of the dipper stick.

Under these circumstances the dipper is'out of control ofv the. hoistingcable 44' and some means must be provi e dipper to such positionj.Inasmuch asthe dipper and dipper stick together form a compoundpendulurmit will not require a very large force to overcome theunbalanced wei ht of the dipper, and this force is easily app ied bymeans of the arrangement of 1 cable and weight shown in Fig. 6, in whichthe dipper stick is shown in the position inquestion. In this figure,the cable 63 is fastened to the end of the dipper stick 24 at'64, and

runs-over the sheave 65 which is mounted near the end of the boom 20.Passing over.

this sheave the cable continues in 'a. direction substantially parallelto the boom and is connected at 66 to the weight '67.] This weight isprovided with rollers so 'that it may slide with ease upon suitablew-aysprovided on the boom, and [is so proportioned that itwill swing thedipper an'd dipper stick to the desired discharge position.

When, however, the'dipper is moved into the digging position the weight67 will simply move along the ways, and will not interfere with theproper manipulation of the dipper.

Although I have shown one specific the motion of the auxiliary dipperstic s 38 with, respect to.' the main dipper stick 24, this movement maybe accomplished in a number of different ways without departing from thespirit and scope of my invention.

In Figs. 7 and; e a modification of the tog le mechanism for supportingand contro ing the pivotal movement of the dipper is illustrated. Inthis modification the 1pper is caused to rotate about its pivot. on

the dipper stick under the influence of gravit or. inertia, the movementbeing controlle by coacting sto 3 operating in con-' 1 junction with thetogg e d'to move the In this'modification the dipper 33 is piv-= oted tothe end of the dipper stick 24 at 32, a's'above described. The togglemechanism comprises a link 34 connected to the dipper at 35 and to asector 68 at the point 69. Sector 68 being hinged to the dipper stick at70 forms the second lever of the toggle joint. The circular edge ofsector 68 is rovided with end stops or notches 71 and 2, as well as withthe intermediate stops or notches 7 3. Control lever 74 is pivoted onthe dipper stick at 7 5 and is biased to the position shown in Fig. 7 bymeans of spring 76. The short end of lever 74 is formed into a hook 77adapted to coact with the stops or notches 71,72, and 73 to form a.mechanical latch which firmly locks the toggle mechanism in any of thesepositions which'may be required. A pair of sectors 68 pivoted atopposite sides of the dipper stick and a pair of cooperating links 34;are required, butonly-one set has been shown in the drawings for thesake of clearness.

In order to understand the operation of the apparatus of thismodification, let us assume that the dipper is in the position, A ofFig. 1, in which it is just commencing at digging stroke. The dipper isbeing hauled up by means of the hoisting cable-44:. The

toggle mechanism is in the position shown in Fig. 7 and the mechanicallatch prevents the .i breaking of the toggle so thatfthe may be hoistedup to fill the dlpper and reach the position B of Fig. 1. It is nowdesired to transfer the dipper and its contents to the dumping pos tion.6 and in order to do this without spilling-the contents of thedipper,it must be'rotate'd aboutthe pivot 32. This is accomplishedeither whilethe dipper is in position B, or as it is being lowered toward positionC, by pulling upon the rope 7 8 attached to the endot lever 74 whichdisenga es hook 77 from notch 71. Inasmuch as t e" dipper and dipperstick are supported entirely by cable 441 this disengagement of thelatch will allow the weight of the dipper stick and dipper to cause-thebreaking of the toggle mechanism, the sector 68 rotating about pivot 70to the position shown in Fig. 8 where the book 77 will slip behind stop72 and lock the dipper. in this position. The movement of p necessary toswing the dipper through a inclined chute.

be inexactly the opposite direction to the forces existing in thismechanism when the dipper was supported by the cable, as for horizontalangle in order to discharge its contents into the receiving vehicle, andit is also unnecessary to hoist the dipper, together with its load, toa'height which is suflicient to cause the loadto slide'down an Insteadof these unnecessary movements the dipper is moved in practically'astraight line from the point of completion of the digging stroke to thedischarge osition. When digging in a bank of usual lieight, thepowernecessary for this transportationof material will be furnished in largemeasure at least, by the material itself, while .descendin with thedipper toward the place of disc marge, As soon as the material isdischarged the dipper is moved in substantially a straight line to thepoint of commencementof the next digging stroke.

Furthermore, it is unnecessary to provide a special type of dipper sincethe standard type is readily adaptable for use. Neither is it necessaryto increase the number of men re 'ulred to operate the shovel, as thecontro s of all the various mechanisms are arranged within the reach of,and are Within thecapacity of a single operator. It should trolling therelative motion also be noted that certain characteristics of thepowersho'vels,"0r excavators, which are in use at present, aremaintained, for example, the turntable feature which enables the shovelto dig in any vertical plane.

'I claim:

, L'In an excavator, a dipper, a dipper stick, means for movablymounting the dipper on the dipper stick, and means for conof the dipperand the dipper stick.

In an excavator, a' dipper, a dipper stick, means for movably mountingthe dipper on the dipper stick, and means including a' toggle joint forcontrollin the relative motion of the dipperon the dipper stick.

In anexcavator, a dipper, a dipper stick, means for movably mounting thedipper on the dipper stick, and meansifor con-/ trolling the relativemotion of the dip er and the di per stick, said means including a togglejomt'adapted to be approximately adapted to be broken in the dumpingposi tion thereof.-

4. In an excavator a dipper, a dip or stick, means for movably mountingthe ipper on the dip or stick, and means for con trolling the re ativemotion of the dippera toggle joint and means automatically con trolledfor breaking the toggle. r

6. In an excavator a receiver for excavated material located centrallyof the digging range of the excavator, a dipper stick carryin levercon-' adipper at its end, a boom on' which t e dipper stick is mountedat a level above that of the receiver for the excavated material, andmeans for actuating the dipper substantially in a vertical plane througha complete digging cycle to gather. up and deliver excavated material tothe receiver.

7. In an excavator, a dipper stick carry,- ing a dipper at its end, aboom on which the dipper stick is mounted at a point substantiallyvertically above the discharge position of the dip r, and means foractuating the dipper su stantially in a vertical plane through acomplete digging cycle.

8. In an excavator, a dipper stick carrying a dipper at its end, ahopper for receiving the excavated material, a boom on which the dipperstick is mounted at a point substantially vertically above the hopper,means for actuating the dipper substantially in a vertical plane-to fillthe dipper with excavated material and to transfer said material to thehopper.

9. In an excavator, a dipper stick carrying a dipper at its end, a boomon which the dipper stick is mounted at 21 int substantially verticallyabove the dlscharge position of the dipper, means for actuating thedipper substantiall in a vertical plane through a complete igring cycle,and means for maintaining the ipper in a substantially upright positionduring its movement from the point of completion of the digging stroketo the discharge position.

10. In an excavator, a dipper, means for actuating said dipper through acomplete digging cycle, and means for maintaining said dipper in asubstantially upright position durin the portion of said diggm cycle inWhi the dipper carries excavate material.

set in the digging position of the dipper, and 11. An excavatorcomprising, a body, a i

gather up material to be excavated and for moving the thus filled dipperin a substantially straight path from the point of completion of thedigging stroke to the discharge position.

digging dipper, means for forcing the dipper outwardly from theexcavator body to gather up material to be excavated and for movingthe'thus filled dipper in a substantially straight path from the pointof completion of the digging stroke to the discharge position, and meansfor maintaining the dipper in a substantially upright position duringsaid movement.

13. An excavator comprising a body, a boom, a dipper, a dipper-stick,means for movin the dipper in a substantially straight path rom thepointof completion of the digging stroke to the discharge position, and

automatic means for maintaining the dipper 1n a substantially uprightposition durlng said movement. a

I 14. An excavator having a' dipper and a centrally located dischargeopening, and provided with means for moving the dipper into dischargeposition relative to said opening, and means for maintaining the dipperin afsubstantially upright position while it is moved to the dischargeposition.

15. In an excavator, a body a boom, a' ipper stick.

central dischar e hopper, a

om, a dipper attached to the dipper stick and manipulated by connectionswith the boom to move outwardly from the excavator body to gather upmaterial to be excavated and to moveinwardly to discharge its load intothe said hopper.

16. An excavator comprising, a body, a boom mounted thereon, a centraldischarge hopper, a dipper stick carried by the boom,

a dipper supported by the dipper stick,

means for moving the dipper outwardly from the excavator body to gatherup material to be excavated and inwardly to dis-.

charge said material into said hopper and means for maintaining thedipper in a substantially upright position as it is moved to saiddischargeposltion.

17. In an *excavator, a body, a boom mounted thereon, a dipper stickcarried by the'boom, a dipper supported b the dipper stick, means formoving the ippero'utwardly to gather up material to be excavated andinwardly so as to dischargesaid material into a centrally locatedreceiver,

and means for maintaining the dipper in a substantially upright positionto prevent the spilling of its contents as the dipper 1S moved from thepoint of completion of the digging stroke to the centrally locateddischarge position.

toward the boom.

25. excavator comprising a body, a.

dipper stick, and means for moving the dipper relative to the dipperstick to prevent the I spilling of its contents as the dipper is 12. Anexcavator comprising, a body, a

moved to the dischargeposition.

19. An excavator comprising, a body, a boom, a main dip er stickoperably mounted on the boom, a dipper movably mounted on said dipperstick, an auxiliary dipper stick carried by the main dipper stickfor'varying the position of the dipper relative to the main dipperstick, and means for actuating both llipper sticks.

20. An excavator comprising, a body, a boom, :1 main dipper stickoperably mounted on the boom, a dipper movably mounted on said dipperstick, an auxiliary dipper stick carried by the main dipper stick forvarying the position of the dipper relative to the main dipper stick andmeans for. simultaneously actuating both dipper sticks.

21. 'An excavator comprising, a body, a boom, a main dipper stickoperably mounted on the boom, a dipper pivoted on said dipper stick, anauxiliary dipper stick car ried by the main dipper stick and ada ted tovary the angular position of the ipper, means for operatin the maindipper stick and means for IIIOVlIlg the auxiliary dipper stickrelatively to the main dipper stick.

'22. An excavator comprisin a boom, a main dipper stick, a dipperpivoted to the main dipper stick and an auxiliary dipper stickautomatically actuated to rotate the dipper about its towardtheboom.

23. An excavator comprising a-ibody, a boom, a main dipper stick, adipper-pivoted to the mainsdipper-stick, an auxiliary dipper stickconnecttadtofthe dipper through a bell crank and lever, said auxiliarydipper stick being automaticallyfactuated to rotate the dipper aboutitsv pivotas vthe dipper is moved toward the boom;

pivot as the dipper is moved 24. An excavator-icomprisin' "a body, aboom, adipperstiek, adip r pivotedto the 7 main dip er stick, an auxiarydipper stick,

connects tov thev dipper through a toggle mech anism, said auxiliarydipper stick being automatically actuated to rotate the dipper aboutits"pivot as the dipper is {moved boom, a main dipper stic a dipper pivotedthereto, an auxiliary dipper stick adjacent said main-dipper stickadapted by longitudinal movement to rotate the dipper about its pivot,and automatic means or moving the said auxiliary dipper stick rela-vtive to the main'dip er stick as is drawn toward the m.

the dipper dipper stick being 26. An excavator comprisin a body, a boom,a main dipper stick opera bly mounted on the boom, a dipper ivoted onsaid clipper stick, an auxiliary ip er stick adjacent 5 the main dipperstick an adaptedto vary the angular position of the dipper, a shippershaft mounted on the boom, inions on said shaft engaging'racks on t erespec-' tive handles, the pinion operating the aux- 1 iliary dipperstick being of larger diameter than the pinion operating the main dipperstick.

27. An excavator comprising, a body, a

I boom, a centrally located discharge opening, 1 a main dipper stickoperably mounted on the boom, a dipper pivoted on said dip er stick,anauxiliary d1 per stick carrie by the main dipper stick and connectedto the dipper by means of a bell crank mechanism,

means for operating the main dipper stick to move the dip er todischarge position over the central y located opening, and

means for simultaneously moving the auxiliary dipper stick relatively tothe main dipper stick. f Y

28. An excavator comprising a body, a boom,,a maindipper stick, a dipperpivoted thereto, an auxiliary dipper stick adjacent said main dipperstick and ada ted by 0 longitudinal movement to rotate t e dipper aboutits pivot, a shipper shaft carried on the boom equipped with pinionsengaging racks on the main and auxiliary dilpper stick, the pinion foractuating the auxi lary the pinion actuatmg the main dipper stick; 29 Anexcavator comprising, a body, a turntable carrying a boom, a hoppercarried by the turntable in front of the boom, a

main dipper stick directly connected to the dipper, an auxiliary dipperstick connected to the dipper by a bell-crank mechanism mounted on themain di per stick, means for hoisting the dipper and means forsimultaneously reciprocating the dipper ,sticks' and for moving theauxiliary lpper stick relative to the main dipper stick, whereby thedipper is operated to dig and to dis-' charge its load into the hop er.

30.-In an excavating mac ine, a body, a

boom, a turntable having a central discharge opening with a movabledumping platform cooperating therewith, a dipper mounted upon a dip orstick carried by the boom,

connections etween the boom and-the dip- 'per for .manipulatinthe dipperto dis charge its load upon t eedumping platform,

dipper about its pivot and means for raising said platform so as todischarge the load through the central Opening- 1 i 31. In anexcavatingmachine,a body, a

boom, a turntable having a central'discharge' opening with a movabledumping platform cooperating therewith, a dipperstick carof largerdiameter than tate the dipper about its ried by the boom, a'dipperattached to the dipper stick and manipulated by connections .with. thebOOlIlto discharge its load upon the dumping latform, means forrelieving the shock o discharge to said latform and means for causingsaid plat orm to discharge into said central opening.

32. In an excavating machine, a body, a

causin said platform to discharge into said centra opening.

33. In an excavator, a I dip r stick, a dipper, a centralhopper locatedbehind-the gravity position of the dipper stick, means for moving thedipper from the excavating position to the dumping position, includingpositive means for moving the dipper stick beyond its gravity position.

34. In an excavator, a dip r stick, a dipper, a-central hopper locatebehind the gravity position of the dipper stick, means for moving thedipper from the excavating position to the dumping osition, said meansmcluding a rope secured to the upper 'portion of the dipper stick andrunning over .a fixed pulley and a weight attached to said P v 35. In anexcavator, a boom, a dipper stick, a dipper, a central ho per locatedbehind the gravity position 0? the di per stick, means for moving thedipper em the excavating position to the dumping position, said meansincluding a rope connected to the'upper portion of the dip er stick andrunning over a pulley on the boom, and a weight slidable onsaid boom andattached to said 'ro 36. An excavator com rising, a body, a boom, a maindipper stic a dlpper pivoted to the main dipper stick, and an auxiliary,

dipper stick automatically actuated to roivotas the dipper is moved awayfrom the ioom;

37. An excavator com rising, a body, a boom, a main dipper stic to themain di per stick, an auxlhary dipper stick connected to the dipperthrough a bell crank lever, said auxiliary dipper stick beingautomatically actuated to rotate the as the dipper is moved away fromthe boom.

-38. An excavator comprising, a bod a boom, a dipper st1ck,,a dipperpivots tothe main dipper stick, an auxiliary diplper stick connectedtoQthe dipper throng toggle mechanism, said auxiliary dipper a dipperpivoted stick being automatically actuated to rotate the dipper aboutits pivot as the dipper i moved away from the boom. Y

39. An excavator comprising, a body, a

5 boom, a main di per stick, a dipper pivoted thereto, an auxi larydipper stick adjacent said main dipper stick adapted by longitudinalmovement to rotate the dipper about its pivot, and automatic means formoving the auxiliary dipper stick relative to the 1 main dipperstick asthe dipper is moved away from the boom. In testimony whereof I afiix mysignature.

PERCY H. THOMAS.

